A positive charge of 18nC is evenly distributed along a straight rod of length 4.0 m that is bent into a circular arc with a radius of 2.0 m. Find the magnitude of the electric eld at the center of curvature of the arc

Respuesta :

Explanation:

Formula for angle subtended at the center of the circular arc is as follows.

           [tex]\theta = \frac{S}{r}[/tex]

where,   S = length of the rod

              r = radius

Putting the given values into the above formula as follows.      

                [tex]\theta = \frac{S}{r}[/tex]

                             = [tex]\frac{4}{2}[/tex]

                             = [tex]2 radians (\frac{180^{o}}{\pi})[/tex]

                             = [tex]114.64^{o}[/tex]

Now, we will calculate the charge density as follows.

                 [tex]\lambda = \frac{Q}{L}[/tex]

                            = [tex]\frac{18 \times 10^{-9} C}{4 m}[/tex]

                            = [tex]4.5 \times 10^{-9} C/m[/tex]

Now, at the center of arc we will calculate the electric field as follows.

                 E = [tex]\frac{2k \lambda Sin (\frac{\theta}{2})}{r}[/tex]

                     = [tex]\frac{2(9 \times 10^{9} Nm^{2}/C^{2})(4.5 \times 10^{-9}) Sin (\frac{114.64^{o}}{2})}{2 m}[/tex]

                      = 34.08 N/C

Thus, we can conclude that the magnitude of the electric eld at the center of curvature of the arc is 34.08 N/C.